Electric welding-machine.



W. C. LINDEMANN & K. D. CAMP.

ELECTRIC WELD1NG MACHINE.

APPLICATION FILED FEB.18.1913.

1,155,497. Patented Oct. 5, 1915.

2 SHEEIS-SHEET I.

W. CELINDEMANN & K. 0. CAMP.

ELECTRIC WELDING MACHINE.

APPLlCATiON FILED FEB.18. 1913.

1,155,497 I Patented Oct. 5, 1915.

2 SHEETSSHEET 2.

Q u /z//%/- UNITED STATES PATENT OFFICE.-

. WALTER c. LINDEJDVIANNIAND KEY D. cAnn'oF MILWAUKEE, wIscoNsIN, AssIeNoRs TO J.-LINDEMA NN & HOVERSON (10., F MIL WAUKEE, WISCONSIN.

ELECTRIC WELDING-MACHINE.

To all whom it may concern 7 Be it known that we,.WAL'rER C. LINDE- MANN and :KEY'D. CAMP, both citizens of the United States, and residents of lVfilwau kee', in the county of Milwaukee and State v of Wisconsin, have invented certain new a and usefullmprovement's in Electric Welding-Machines; and we do hereby declare that the following isa; fulL-c'lear, and exact description *thereof.

Our invention consists-in what is herein particularly set forthwith reference to the accompanying drawings'and pointed out in the elaim's'of this specification, its object being to provide electric spot-welding ma chines, having greater" durability, simpler operation, increased efficiency and requiring less adjustment than .those'of ordinary construction, each of our improved machines being so constructed as-to be operated by power and usable for electric spot-welding of materials that have heretofore been so welded only by manually operated machines;

' an especialfeature' of'our invention being .a cam-actuatedreciprocative crosshead and the cam so contoured. as-to permit of a dwell of thecrosshead fora time at the end'of its stroke in each direction, but especially at the end of its downstroke, where said dwell is sufficiently long as topermit of the make and breakof an' electric welding-circuit, by

' especially devised 'means, prior to the time the aforesaid crosshead starts 'upon its up ward travel, whereby ample provision is had .for the completion. of aweld of material that has beenpreviou'sly gripped between two If electrodes of saidzc'ircuit;

' Figure 1 of the drawings represents a side elevation .of one of our improved electric spot-welding machines .partly' in section, the section-beingindicated by line-11 in the next "described illustration; Fig. 2, a transversesectional View of a fragment of the machine indicated by line 22 in Figs. 1 and 3; Fig. 3,9. horizontal section of the same fragment of the machine indicated by line 33 in Figs. 1 and 2; Fig. 4, a transverse sectional view of another detail of the machine indicated by line 4:4 in Fig. l, and

Fig. 5, a. diagram -of the electric-welding circuit.

a forwardly projecting upper arm 7 is suitably secured, and likewise secured in connec- Specifieation of Letters Patent. 1

lel andthe upper one. fashionedat its forward end to provide an angular clearance space and vertical cheeks 9. The arm 7 is provided with bearings for a shaft 10 haw ing a drive-pulley 11 and astart-and-stop collar 12 rigid. therewith, a spring-andtreadle controlled latch-rod 13 engageable with the collar 12 being shown guided in [a bracket 14 of "said arm. The detailof mechanism for controlling start and stop of the aforesaid-shaft constitutes no part of .our present invention, a1'ld ,any suitable means may be .employed for'the same-purpose, it being understood that a drivingbelt operates the pulley, and that said pul-.

ley runs idle when said shaft is not in action.

' Keyed on the forward end of the shaft '10 is a circular cam 15 within an angular frame 16 guided vertically in another angular frame 17 for WlllClInVBItlCtil guides '18 are provided, v these guides being held in detachable connection with the cheeks 9- of the arm 7 by screws. The framesconstitutea crosshead .80

and, as a matter of detail, the inner frame is provided with tongues engaging grooves in the outer frame and detachably held in place byface-plates 16 fastened by screws to said outer frame. I

. The inner frame of the crosshead is supported on compressionsprings 19, and opposed by an adjusting turret screw 21 depending from the outer frame of said crosshead. Attached to the crosshead is a yield- I ing electric :conductor- 22 forming part of a secondarycircuit of a transformer provided, with the machine. The conductor is shown as being composed of, laminated copper strips, and clamped on its forward free end under saidcrosshead, central of the same,.

is the shank 23 of a separable holder 24: for an electrode 25 opposing another'electrode 26 clamped between the forward'end of the arm 8 and a block 27 bolted thereto, the op- 9 posing faces of said arm and block being recessed to engage the interposed electrode,

, Fast on the shaft 10 is an insulator-ring 28, and fitted tight on the ring is a contactsleeve 29 having a lateral lug 30. In con- 10.,

stant touch with the sleeveis a brush 31 for which a holder 32 issupported by an in-' sulating plate 33 attached to a block 34:,

the block being insulated on the bracket 1 1 aforesaid. Pivoted in a longitudinal groove I Patented 00t- 5,1915. Application filediFebruary 18 1913, 7 Serial No.'749,191. I

- sleeve 29, said brush and rocker being terwiththe conductor 22) as though it were minals of the primary circuit of a transformer, which transformer is indicated at 36 in the diagram Fig. 5. The electrodes 25 and 26 are included in the secondary circuit of the transformer by any suitable electrio practice, this'disposition of said electrodes being illustrated in said, diagram Fig. 5. a 1

The secondary circuit of the transformer is the Welding-circuitof our machine, and in practice the material to be welded is laid in on the electrode"26,-after which the shaft 10 is released by a' depression of the treadle 37, whereupon the cam 15 is rotated'to depress the crosshead and'the electrode 2 5, the normal position of the 111g 30 of the contactsleeve 28 being such, as shown in Fig. 1, that it does not come into touch'with the rocker terminal 35 to close said- Welding-circuit, as shown in Fig. 4, until subsequent tofa gripping of said work between said electrodes. The springs 19 are employed between the frames 16, 17 of the crosshead so that materials of variable thickness may be interposed between the electrodeswithout changing the adjustment of said crosshead, but said springs have no bearing on the time interval allowed fora welding operation, thisbeing taken care of entirely by. the timing of the cam 15. The action of the cam 15 takes place upon the inner frame 16-of the crosshead moving the entire crosshead (together one piece until'themate'rial to be welded is gripped between the electrodes whereupon, due to the cam action, the crosshead re-i mains stationary for a definite predetermined interval of time, then starts its travel back to its original position. Thespri'ngs .19 acting between inner frame 16 and outer frame 7 17 compensate for variations thickness of the material to be welded and the material between the. electrodes and while the crosshead is at rest, the lug-30 extending from the sleeve 29, in revolution during the time the contact lug .30 is in ro-1 tary opposition to the rocker 35', :At the instant-the lug passes the rocker,-theelectric circuits are'brokemwith'a sharp"snap, due to spring action on said rocker-causingthe sameto return to 'no'rmalposition-ythe indewith .the shaft lO, makes contact with the rocker 35 that yields against the spring 37 in opposition thereto. The transformer circuits are now closed and a welding of said material between said electrodes takes place pendent reversemovement of said rocker being suflicient to break any electric-arc that may take place between it and said lugg of the Welding electrodes upon the inter-- posed material, and the operation of the machine is recurrent as long as the aforesaid treadle is held down. i

It will be understood from the foregoing I that ,the circuit --ma ke and break mechanism, complete in itself, consists of the contact-sleeve 29 having the lug 30, the brush 31 and brush-holder 32 on onev sideof the.

circuit, while on the other side of said circuit the spring-controlled rocker 35 is pivoted to permit the necessary amount of -movement at its contact-end, the pivoting being within the groove of the block 34 with the ,pivot so disposed as to provide for the necessary movement of the contact-end or arm of said rocker that extends outward from said groove. The rocker shown is somewhat T-shaped and the block-groove has the bottom thereof beveled in opposite directions to permit of the desired pivotal playof said rocker, but the details of construction of the circuit make and break mechanism may be varied indefinitely from what has been specifically disclosed as an application in an electric circuit of a pair of make and break contact devices one of which is movable past the other transversely thereto, and of which contact devices one at least thereof is yielding to the other and automatically returnable to normal position on the instant of'their clearance. The contact devices aforesaid may be so constructed as to provide for renewal of their wearing surfaces.

We claim:

1. In an electric welding machine, the combination of a driven shaft, a cam therewith, a sliding frame for which stationary guides are provided, anothem sliding frame guided in the one aforesaid and, engaged I I jQbYgthe cam, spring-resistance arranged bethus greater range to the setting ofthe elecv trodes and 1 the adjustment of the crosshead n is afforded. Subsequent to the grippingvof tween the two frames tooppose independent movement of the inner one for a time in one with, a; sliding frame for which stationary guides are provided, anothersliding frame guided in the one aforesaid and engaged by the cam, spring-resistance arranged between the two frames to oppose independent movement of the inner one for a time in one direction, means controlling adj ustme'nt of the inner frame opposite said spring resistance,

guided in the one aforesaid and engaged. by the same, spring-resistance arranged be-' tween the two frames to oppose independent movement of the inner one for a time in one direction, a turret-screw depending from the outer frame against the inner one opposite said spring resistance, a welding-circuit electrode movable with the crosshead formed by said frames, an opposing electrode in the same circuit, and means with the shaft for effecting an automatic make and break of said circuit during the interval of time the material to be welded is gripped between said electrodes and during whichinterval of time said inner frame may have independent yield to said cam against said spring-resistance.

In testimony that we claim the foregoing we have hereunto set our hands at Milwaukee in the county of Milwaukee and State of \Visconsin in the presence of two witnesses.

WALTER C. LINDEMANN. KEY D. CAMP. Witnesses:

EDWIN HENES, FERD. A. HOYA. 

